A mass balancing mechanism comprising a balancing shaft of the pre-cited type is disclosed in the document EP 1 081 410 B1 which is considered to be generic. To put it briefly, the proposed balancing shaft is based on the knowledge that, in a peripheral portion situated opposite the mass center of gravity, the bearing peg of the balancing shaft is subjected only to comparatively low loading and, consequently, the recess extending in this portion of the periphery between the cylindrical bearing peg sections does not detract from the bearing capacity of the bearing peg. This creates two significant advantages with regard to the goal of always keeping the mass of the balancing shaft as low as possible. On the one hand, the mass of the bearing peg is decreased in correspondence to the recess and, on the other hand, the removal of the mass of the recess leads to an enlargement of the distance of the mass center of gravity from the axis of rotation of the balancing shaft. The second advantage provides constructional scope for enhancing the unbalanced mass effect of the balancing shaft without altering the mass, or for a further reduction of the mass of the balancing shaft while maintaining a constant position of the mass center of gravity by an additional removal of material. It is clear that any other desired configurations are likewise feasible within these limits.
However, in the case of the mass balancing mechanism of the cited document, the balancing shaft is hydro dynamically slide-mounted on its bearing peg. A drawback of this resides, on the one hand, in the typical frictional losses of such sliding bearings, which can be considerable particularly at low temperatures and/or in combination with a highly viscous hydraulic medium, and can thus lead to an additional fuel consumption of the internal combustion engine that is relevant not only to the driving cycles. On the other hand, the potential of the above-mentioned advantages can only be restrictedly exploited because, with a view to building up a lubricant film with an adequate bearing capacity in the hydrodynamic sliding bearing, the bearing peg sections cannot have a random thin configuration.